Preterite vs Imperfect: The Two Sentences That Sort It Out

If there's one bit of Spanish grammar that makes people want to throw their textbook across the room, it's the preterite and the imperfect. Both talk about the past. Both translate as "I did" or "I was doing" depending on the day. And the rules in most books go on for pages.

Here's the good news: you can carry almost all of it around in one sentence.

The anchor sentence

Comía una manzana cuando sonó el teléfono.

(I was eating an apple when the phone rang.)

Look at the two verbs.

• Comía is the imperfect. It's the background, the thing that was going on. There's no clear start or finish. You were just munching away.
• Sonó is the preterite. It's the event. It happened once, at a specific moment, and it broke into the background.

If you picture it as a film, the imperfect is the scene and the preterite is the action. Learn this sentence by heart and, when you're stuck, ask yourself: is this the apple or the phone?

When to use the imperfect

Think of the imperfect as the "setting the scene" tense. Use it for:

Background and descriptions:

Hacía sol y la playa estaba llena. (It was sunny and the beach was packed.)

Things you used to do:

De pequeño, iba a la playa todos los veranos. (When I was little, I used to go to the beach every summer.)

What was happening when something else happened:

Leía en el sofá cuando llegó mi hermana. (I was reading on the sofa when my sister arrived.)

Age and time in the past:

Tenía diez años. Eran las tres de la tarde. (I was ten. It was three in the afternoon.)

A handy anchor for habits is De pequeño, iba a la playa todos los veranos. If you can stick "used to" in front of the English, it's almost always imperfect.

When to use the preterite

The preterite is the "and then this happened" tense. Use it for:

One-off, finished actions:

Ayer comí paella. (Yesterday I ate paella.)

A list of events, one after another:

Me levanté, me duché y salí de casa. (I got up, showered and left the house.)

Something that interrupted the background:

...cuando sonó el teléfono.

Actions with a clear start, end or length:

Viví en Sevilla dos años. (I lived in Seville for two years.)

That last one catches lots of people out. You might think living somewhere sounds like background, but once you put a time limit on it (two years, all summer, until 2020), it becomes a finished block, so it's preterite.

Trigger words (handy, but don't trust them blindly)

Some words often go with one tense or the other:

Usually imperfect	Usually preterite
siempre (always)	ayer (yesterday)
todos los días (every day)	anoche (last night)
a menudo (often)	el año pasado (last year)
de pequeño (when I was little)	de repente (suddenly)
mientras (while)	una vez (once)

They're a useful clue, but they're not a rule. Ayer hacía frío (it was cold yesterday) is imperfect because it's describing the weather, even with ayer in there. Always come back to the question: scene or action?

A quick memory trick

Here's one my students like: the imperfect is a video, the preterite is a photo.

The imperfect shows something moving and ongoing, like a video playing in the background. The preterite is a snapshot: click, done.

Mientras cocinaba (video), se fue la luz (photo). While I was cooking, the power went off.

Verbs that change meaning

A few verbs shift meaning depending on the tense, and these are great for anchor pairs:

• Conocía a Ana. (I knew Ana.) / Conocí a Ana en una fiesta. (I met Ana at a party.)
• Sabía la verdad. (I knew the truth.) / Supe la verdad ayer. (I found out the truth yesterday.)
• No quería ir. (I didn't want to go.) / No quise ir. (I refused to go.)

The imperfect gives you the state. The preterite gives you the moment it started or the decision.

Common mistakes

• Using the imperfect for everything that "feels long". If it's finished and you've given it a time frame, it's preterite: Estudié tres horas.
• Using the preterite for descriptions. "The hotel was lovely" is a description: El hotel era precioso.
• Forgetting about the present perfect. In Spain, if the time period isn't finished (hoy, esta semana), people usually say he comido, not comí. That's a different post, but keep it in mind.

Practise it with your own sentences

The quickest way to get comfortable is to write a few apple-and-phone sentences about your own life. Veía la tele cuando llamó mi madre. Caminaba por la calle cuando vi a mi ex. The sillier, the better.

In the Fun Learning Spanish app you can save these as anchor sentences, add your own vocab, and practise with sentence puzzles and quizzes built from your words. Pico, the AI helper, can check your sentences and suggest new ones if you're running out of ideas. It's free to start at app.funlearningspanish.com.

The short version

Remember the apple and the phone. Comía una manzana cuando sonó el teléfono. Background is imperfect, events are preterite. Video, then photo. When in doubt, go back to the apple.